Layered silicate flame retardant compositions

ABSTRACT

The invention relates to flame retardant compositions that contain mixtures of melamine polyphosphates with layered silicates added to the polymer substrates, particularly polyamides.

The present invention relates to flame retardant polymer compositionswhich comprise mixtures of melamine polyphosphates with layeredsilicates. The compositions are especially useful for the manufacture offlame retardant compositions based on thermoplastic polymers.

Flame retardants are added to polymeric materials (synthetic or natural)to enhance the flame retardant properties of the polymers. Depending ontheir composition, flame retardants may act in the solid, liquid or gasphase either chemically, e.g. as a spumescent by liberation of nitrogen,and/or physically, e.g. by producing a foam coverage. Flame retardantsinterfere during a particular stage of the combustion process, e.g.during heating, decomposition, ignition or flame spread.

The addition of fillers to organic materials, especially polymers, isknown and is described for example in Hans Zweifel (editor), PlasticsAdditives Handbook, 5th Edition, pages 901-948, Hanser Publishers,München (Germany) 2001. The use of fillers in polymers has the advantageof improving, for example, the mechanical properties, especially thedensity, hardness, rigidity (modulus) or reduced shrinkage of thepolymer.

Using extremely small filler particles (<200 nm), so-called nano-scaledfillers, mechanical properties, heat distortion temperature stability orflame retardant property of the polymers can be improved at a much lowerconcentration typically of 2 to 10% by weight compared to 20 to 50% byweight with the micro-scaled normal filler particles. Polymerscontaining nano-scaled fillers combine favourable mechanical propertieslike strength, modulus and impact, and show improved surface qualitieslike gloss, lower tool wear at processing and better conditions forrecycling. Coatings and films comprising nano-scaled fillers showimproved thermal stability, flame retardancy, gas barrier properties andscratch resistance.

Nano-scaled fillers possess an extremely large surface with high surfaceenergy. The deactivation of the surface energy and the compatibilizationof the nano-scaled fillers with a polymeric substrate is, therefore,even more important than with a common micro-scaled filler in order toavoid aggregation during processing or conversion of the filled polymerand to reach an excellent dispersion of the nano-scaled filler in thefinal article.

There is substantial recent literature on organic-inorganicnano-composites based on layered silicates such as montmorillonite andsynthetic polymers. Polyolefin nano-composites have been prepared fromorganic modified clays. The clays used are generally modified with alkylor dialkyl ammonium ions or amines or in a few cases other onium ions,like for example phosphonium. The ammonium ion/amine additives areusually incorporated into the clay structure by a separate solution orsuspension intercalation step.

There is still a need for flame retardant compositions with improvedproperties that can be used in different polymer substrates. Increasedstandards with regard to safety and environmental requirements result instricter regulations. Particularly known halogen containing flameretardants no longer match all necessary requirements. Therefore,halogen free flame retardants are preferred, particularly in view oflower toxicity and less environmental concerns and their betterperformance in terms of smoke density associated with fire. Improvedthermal stability and less corrosive behaviour are further benefits ofhalogen free flame retardant compositions.

It has surprisingly been found that polymers with excellent flameretardant properties are prepared in the event that mixtures of melaminepolyphosphates with layered silicates are added to the polymersubstrate.

The invention relates to a composition, particularly a flame retardantcomposition, which comprises

-   -   a) At least one polyphosphate salt of a 1,3,5-triazine compound        of the formula

-   -   -   Wherein T represents a 1,3,5-triazine compound; and        -   p represents a numeral greater than 3;

    -   b) At least one natural or synthetic phyllosilicate or a mixture        thereof; and

    -   c) A polymer substrate; and

    -   d) Phenolic antioxidants.

The composition defined above for use as a flame retardant is anotherembodiment of the invention.

A preferred embodiment of the invention relates to a composition, whichcomprises

-   -   a) At least one polyphosphate salt of a 1,3,5-triazine compound        (I), wherein        -   p represents a numeral greater than 3;        -   and the 1,3,5-triazine content is higher than 1.0 mol            1,3,5-triazine compound per mol of phosphorus atom;    -   b) At least one layered silicate;    -   c) A thermoplastic polymer substrate; and    -   d) Phenolic antioxidants.

A particularly preferred embodiment of the invention relates to acomposition, which comprises

-   -   a) At least one polyphosphate salt of a 1,3,5-triazine compound        (I), wherein p represents a numeral greater than 10; and the        1,3,5-triazine content is higher than 1.1 mol 1,3,5-triazine        compound per mol of phosphorus atom;    -   b) At least one unmodified layered silicate selected from the        group consisting of montmorillonite, bentonite, beidelite, mica,        hectorite, saponite, nontronite, sauconite, vermiculite,        ledikite, magadite, kenyaite, stevensite, volkonskoite and        hydrotalcite or mixtures thereof;    -   c) A thermoplastic polymer substrate; and    -   d) Phenolic antioxidants.

Another preferred embodiment of the invention relates to composition,which comprises

-   -   a) At least one polyphosphate salt of a 1,3,5-triazine compound        (I), wherein p represents a numeral greater than 10; and the        1,3,5-triazine content is higher than 1.1 mol 1,3,5-triazine        compound per mol of phosphorus atom;    -   b) At least one layered silicate selected from the group        consisting of montmorillonite, bentonite, beidelite, mica,        hectorite, saponite, nontronite, sauconite, vermiculite,        ledikite, magadite, kenyaite, stevensite, volkonskoite,        hydrotalcite, illite, kaolinite, wollastonite, attapulgite,        talcum and silica or mixtures thereof modified by an ammonium,        amine, a phosphonium, sulphonium or siloxane compound;    -   b) A thermoplastic polymer substrate; and    -   c) Phenolic antioxidants.

According to a highly preferred embodiment, the invention relates to acomposition, which comprises

-   -   a) At least one polyphosphate salt of a 1,3,5-triazine compound        (I), wherein        -   p represents a numeral greater than 10;        -   and the 1,3,5-triazine content is higher than 1.1 mol            1,3,5-triazine compound per mol of phosphorus atom;    -   b) At least one unmodified layered silicate selected from the        group consisting of montmorillonite, bentonite, beidelite, mica,        hectorite, saponite, nontronite, sauconite, vermiculite,        ledikite, magadite, kenyaite, stevensite, volkonskoite and        hydrotalcite or mixtures thereof; and    -   c) A thermoplastic polymer substrate selected from the group        consisting of polyamides and copolyamides;    -   d) A phenolic antioxidant selected from the group consisting of        octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate,        pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],        tris(3,5-di-tert-butyl-4-hydroxyphenyl)isocyanurate,        1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene,        triethylene-glycol-bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate],        and        N,N′-hexane-1,6-diyl-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide].

The compositions according to the invention attain excellent ratings,according to UL-94 (Underwriter's Laboratories Subject 94), and otherexcellent ratings in related test methods where conventional flameretardants tend to fail and at the same time very good mechanicalproperties.

Compositions of flame retardants and polymers tend to increased meltviscosity as compared to the pure polymers due to interactions ofchemical groups of the flame retardant with the polymer chain. This hasthe effect that the amide group of a polyamide may interact with aphosphate group of a flame retardant. However, an increased meltviscosity reduces the throughput and cycle time during processing andmanufacturing of polymer articles, requires higher processingtemperatures or higher energy cost. The present compositions of layeredsilicates and flame retardants, e.g. melamine derivatives, show areduced influence on the melt viscosity and on the processing behaviourand, therefore, allow transforming processes close to the pure polymer.

Component a)

In a polyphosphate salt of a 1,3,5-triazine compound of the formula (I),the 1,3,5-triazine compound is the basic salt component which isselected from a variety of compounds within the scope of thatdefinition, such as melamine, melam, melem, melon, ammeline, ammelide,2-ureidomelamine, acetoguanamine, benzoguanamine or diaminephenyltriazine.

Melamine polyphosphate and a process for preparing this salt aredescribed, inter alia, in WO 97/44377. According to this reference,melamine polyphosphate having a solubility of 0.01 to 0.10 g per 100 mlwater at 25° C., a pH between 2.5 and 4.5, and a melamine/phosphorusmolar ratio of between 1.0 and 1.1, may be obtained at 25° C. as aqueousslurry of 10.0 wt %.

The preparation of a polyphosphate salt of a 1,3,5-triazine compoundwherein the number p of the average degree of condensation is between 5and 200, and the 1,3,5-triazine content amounts to 1.1 to 2.0 mol of a1,3,5-triazine compound is described in WO 00/02869.

This reference discloses a process which involves the conversion of a1,3,5-triazine compound with orthophosphoric acid into itsorthophosphate salt, followed by dehydration and thermal treatment toconvert the orthophosphate salt into a polyphosphate of the1,3,5-triazine compound.

The p-value of the polyphosphate salts is preferably above 10,particularly between 40 and 150, and the ratio of 1,3,5-triazinecompound per mol of phosphorus atom is preferably between 1.2 and 1.8.Further, the pH of aqueous slurry of salts of 10.0 wt %, as preparedaccording to this method, is greater than 4.5 and preferably at least5.0. The referenced pH value is determined by introducing the salt andpure water at room temperature into a 300-ml beaker, stirring theresulting aqueous slurry for some 30 minutes, and then measuring the pH.

This thermal treatment is preferably performed at a temperature of atleast 300° C., and preferably at least 310° C. In addition toorthophosphates of 1,3,5-triazine compounds, other 1,3,5-triazinephosphates may also be used, including, for example, a mixture oforthophosphates and pyrophosphates.

The orthophosphate of the 1,3,5-triazine compound may be prepared in avariety of other processes. The preferred process involves adding the1,3,5-triazine compound to an aqueous solution of orthophosphoric acid.An alternative process involves adding orthophosphoric acid to anaqueous slurry of the 1,3,5-triazine compound.

Some polyphosphate salts of a 1,3,5-triazine compound are commerciallyavailable, such as melamine polyphosphate (Melapur® 200, Ciba Inc, BaselSwitzerland).

The above-mentioned polyphosphate salt is advantageously contained inthe composition of the invention in an amount from about 0.1% to about45.0% by weight of the organic polymer substrate; for instance about1.0% to about 40.0%; for example about 5.0% to about 35.0% by weight ofthe polymer or based on the total weight of the composition.

Component b)

Component b) is filler in the size of nano-particles (nano-scaled filleror nano-particulate-filler). Preferred fillers are, for example, naturalor synthetic phyllosilicates or mixtures of such phyllosilicates.Fillers of special interest are for example layered silicate. Of veryspecial interest are compositions comprising as component b) at leastone unmodified layered silicate selected from the group consisting ofmontmorillonite, bentonite, beidelite, mica, hectorite, saponite,nontronite, sauconite, vermiculite, ledikite, magadite, kenyaite,stevensite, volkonskoite, hydrotalcite, illite, kaolinite, wollastonite,attapulcite, talcum and silica or mixtures thereof.

Of specific interest are compositions comprising as component b) atleast one unmodified layered silicate selected from the group consistingof montmorillonite, bentonite, beidelite, mica, hectorite, saponite,nontronite, sauconite, vermiculite, ledikite, magadite, kenyaite,stepvensite, volkonskoite, hydrotalcite, illite, kaolinite,wollastonite, attapulgite, talcum and silica or a mixture thereof.According to an alternative embodiment, Component b) can be modified bya modification agent, such as, for example, an ammonium, an amine, and aphosphonium, sulphonium or siloxane compound. Examples of suitablemodification agents for nano-clays are for example:

-   -   Amine and ammonium compounds, for example,        distearyldimethylammonium chloride,        stearylbenzyldimethylammonium chloride, stearylamine,        stearyldiethoxyamine or aminododecanoic acid [e.g. Nanofil®,        commercially available from Rockwood Additives Ltd., Germany];        dimethyl ditallow ammonium, trioctylmethyl ammonium,        dipolyoxyethylenealkylmethyl ammonium or        polyoxypropylenemethyldiethyl ammonium [modified Somasif®,        commercially available from CO—OP Chemicals, Japan];        octadecylamine, triethoxysilanyl-propylamine [Nanomer®,        commercially available from Nanocor, USA], polyalkoxylated        ammonium compounds, such as, for example, octadecyl        bis(polyoxyethylene[15]amine [Ethomeen®, commercially available        from Eastman, USA] or octadecyl methyl        bis(polyoxyethylene[15]ammonium chloride [Etoquad®, commercially        available from Eastman, USA] or the corresponding free amines;    -   Phosphonium compounds, for example tetrabutylphosphonium or        octadecyl triphenyl phosphonium [commercially available from        Eastman, USA];    -   Others, for example, triethoxyoctylsilane [Nanomer®,        commercially available from Nanocor], ammonium, sulphonium or        pyridinium compounds, as disclosed, for example, in        WO-A-01/04050 or WO-A-99/67790; block or graft copolymers, such        as, for example PEO-b-PS or poly-4-vinylpyridine-b-PS; or        solvents for swelling, such as, for example, γ-butyrolactone,        2-pyrrolidone, dimethylsulphoxide, diglyme, tetrahydrofuran or        furfuryl alcohol.

The above-mentioned phyllosilicate component is advantageously containedin the composition of the invention in an amount from about 0.1% toabout 45.0% by weight of the organic polymer substrate; for instanceabout 1.0% to about 40.0%; for example about 5.0% to about 35.0% byweight of the polymer or based on the total weight of the composition.

Component c)

The term polymer substrate comprises within its scope thermoplasticpolymers or thermosets, particularly polyamides or co-polyamides. A listof suitable synthetic polymers is given below:

-   1. Polyamides and co-polyamides derived from diamines and    dicarboxylic acids and/or from aminocarboxylic acids or the    corresponding lactams, for example polyamide 4, polyamide 6,    polyamide 6/6, 6/10, 6/9, 6/12, 4/6, 12/12, polyamide 11, polyamide    12, aromatic polyamides starting from m-xylene diamine and adipic    acid; polyamides prepared from hexamethylenediamine and isophthalic    or/and terephthalic acid and with or without an elastomer as    modifier, for example poly-2,4,4,-trimethylhexamethylene    terephthalamide or poly-m-phenylene isophthalamide; and also block    copolymers of the aforementioned polyamides with polyolefins, olefin    copolymers, ionomers or chemically bonded or grafted elastomers; or    with polyethers, e.g. with polyethylene glycol, polypropylene glycol    or polytetramethylene glycol; as well as polyamides or co-polyamides    modified with EPDM or ABS; and polyamides condensed during    processing (RIM polyamide systems).-   2. Polymers of monoolefins and diolefins, for example polypropylene,    polyisobutylene, polybut-1-ene, poly-4-methylpent-1-ene,    polyvinylcyclohexane, polyisoprene or polybutadiene, as well as    polymers of cycloolefins, for instance of cyclopentene or    norbornene, polyethylene (which optionally can be crosslinked), for    example high density polyethylene (HDPE), high density and high    molecular weight polyethylene (HDPE-HMW), high density and ultrahigh    molecular weight polyethylene (HDPE-UHMW), medium density    polyethylene (MDPE), low density polyethylene (LDPE), linear low    density polyethylene (LLDPE), (VLDPE) and (ULDPE).    -   Polyolefins, i.e. the polymers of monoolefins exemplified in the        preceding paragraph, preferably polyethylene and polypropylene,        can be prepared by different and especially by the following        methods:    -   a) Radical polymerisation (normally under high pressure and at        elevated temperature).    -   b) Catalytic polymerisation using a catalyst that normally        contains one or more than one metal of groups IVb, Vb, Vlb or        VIII of the Periodic Table. These metals usually have one or        more than one ligand, typically oxides, halides, alcoholates,        esters, ethers, amines, alkyls, alkenyls and/or aryls that may        be either π- or σ-coordinated. These metal complexes may be in        the free form or fixed on substrates, typically on activated        magnesium chloride, titanium(III) chloride, alumina or silicon        oxide. These catalysts may be soluble or insoluble in the        polymerisation medium. The catalysts can be used by themselves        in the polymerisation or further activators may be used,        typically metal alkyls, metal hydrides, metal alkyl halides,        metal alkyl oxides or metal alkyloxanes, said metals being        elements of groups Ia, IIa and/or 111a of the Periodic Table.        The activators may be modified conveniently with further ester,        ether, and amine or silyl ether groups. These catalyst systems        are usually termed Phillips, Standard Oil Indiana,        Ziegler-Natta), TNZ (DuPont), metallocene or single site        catalysts (SSC).-   3. Mixtures of the polymers mentioned under 2, for example mixtures    of polypropylene with polyisobutylene, polypropylene with    polyethylene (for example PP/HDPE, PP/LDPE) and mixtures of    different types of polyethylene (for example LDPE/HDPE).-   4. Copolymers of monoolefins and diolefins with each other or with    other vinyl monomers, for example ethylene/propylene copolymers,    linear low density polyethylene (LLDPE) and mixtures thereof with    low density polyethylene (LDPE), propylene/but-1-ene copolymers,    propylene/isobutylene copolymers, ethylene/but-1-ene copolymers,    ethylene/hexene copolymers, ethylene/methylpentene copolymers,    ethylene/heptene copolymers, ethylene/octene copolymers,    ethylene/vinylcyclohexane copolymers, ethylene/cycloolefin    copolymers (e.g. ethylene/norbornene like COC), ethylene/1-olefins    copolymers, where the 1-olefin is generated in-situ;    propylene/butadiene copolymers, isobutylene/isoprene copolymers,    ethylene/vinylcyclohexene copolymers, ethylene/alkyl acrylate    copolymers, ethylene/alkyl methacrylate copolymers, ethylene/vinyl    acetate copolymers or ethylene/acrylic acid copolymers and their    salts (ionomers) as well as terpolymers of ethylene with propylene    and a diene such as hexadiene, dicyclopentadiene or    ethylidene-norbornene; and mixtures of such copolymers with one    another and with polymers mentioned in 1) above, for example    polypropylene/ethylene-propylene copolymers, LDPE/ethylene-vinyl    acetate copolymers (EVA), LDPE/ethylene-acrylic acid copolymers    (EAA), LLDPE/EVA, LLDPE/EAA and alternating or random    polyalkylene/carbon monoxide copolymers and mixtures thereof with    other polymers, for example polyamides.-   5. Hydrocarbon resins (for example C₅-C₉) including hydrogenated    modifications thereof (e.g. tackifiers) and mixtures of    polyalkylenes and starch;    -   The homopolymers and copolymers mentioned above may have a        stereo structure including syndiotactic, isotactic,        hemi-isotactic or atactic; where atactic polymers are preferred.        Stereo block polymers are also included.-   6. Polystyrene, poly (p-methylstyrene), poly(α-methylstyrene).-   7. Aromatic homopolymers and copolymers derived from vinyl aromatic    monomers including styrene, α-methylstyrene, all isomers of vinyl    toluene, especially p-vinyl toluene, all isomers of ethyl styrene,    propyl styrene, vinyl biphenyl, vinyl naphthalene, and vinyl    anthracene, and mixtures thereof. Homopolymers and copolymers may    have a stereo structure including syndiotactic, isotactic,    hemi-isotactic or atactic; where atactic polymers are preferred.    Stereo block polymers are also included;    -   a) Copolymers including aforementioned vinyl aromatic monomers        and comonomers selected from ethylene, propylene, dienes,        nitriles, acids, maleic anhydrides, maleimides, vinyl acetate        and vinyl chloride or acrylic derivatives and mixtures thereof,        for example styrene/butadiene, styrene/acrylonitrile,        styrene/ethylene (interpolymers), styrene/alkyl methacrylate,        styrene/butadiene/alkyl acrylate, styrene/butadiene/alkyl        methacrylate, styrene/maleic anhydride,        styrene/acrylonitrile/methyl acrylate; mixtures of high impact        strength of styrene copolymers and another polymer, for example        a polyacrylate, a diene polymer or an ethylene/propylene/diene        terpolymer; and block copolymers of styrene such as        styrene/butadiene/styrene, styrene/isoprene/styrene,        styrene/ethylene/butylene/styrene or        styrene/ethylene/propylene/styrene.    -   b) Hydrogenated aromatic polymers derived from hydrogenation of        polymers mentioned under 7, especially including        polycyclohexylethylene (PCHE) prepared by hydrogenating atactic        polystyrene, often referred to as polyvinylcyclohexane (PVCH).    -   c) Hydrogenated aromatic polymers derived from hydrogenation of        polymers mentioned under 7a. Homopolymers and copolymers may        have a stereo structure including syndiotactic, isotactic,        hemi-isotactic or atactic; where atactic polymers are preferred.        Stereo block polymers are also included.-   8. Graft copolymers of vinyl aromatic monomers such as styrene or    α-methylstyrene, for example styrene on polybutadiene, styrene on    polybutadiene-styrene or polybutadiene-acrylonitrile copolymers;    styrene and acrylonitrile (or methacrylonitrile) on polybutadiene;    styrene, acrylonitrile and methyl methacrylate on polybutadiene;    styrene and maleic anhydride on polybutadiene; styrene,    acrylonitrile and maleic anhydride or maleimide on polybutadiene;    styrene and maleimide on polybutadiene; styrene and alkyl acrylates    or methacrylates on polybutadiene; styrene and acrylonitrile on    ethylene/propylene/diene terpolymers; styrene and acrylonitrile on    polyalkyl acrylates or polyalkyl methacrylates, styrene and    acrylonitrile on acrylate/butadiene copolymers, as well as mixtures    thereof with the copolymers listed under 7, for example the    copolymer mixtures known as ABS, MBS, ASA or AES polymers.-   9. Halogen-containing polymers such as polychloroprene, chlorinated    rubbers, chlorinated and brominated copolymer of    isobutylene-isoprene (halobutyl rubber), chlorinated or    sulphochlorinated polyethylene, copolymers of ethylene and    chlorinated ethylene, epichlorohydrin homo- and copolymers,    especially polymers of halogen-containing vinyl compounds, for    example polyvinyl chloride, polyvinylidene chloride, polyvinyl    fluoride, polyvinylidene fluoride, as well as copolymers thereof    such as vinyl chloride/vinylidene chloride, vinyl chloride/vinyl    acetate or vinylidene chloride/vinyl acetate copolymers.-   10. Polymers derived from α,β-unsaturated acids and derivatives    thereof such as polyacrylates and polymethacrylates; polymethyl    methacrylates, polyacrylamides and polyacrylonitriles,    impact-modified with butyl acrylate.-   11. Copolymers of the monomers mentioned under 10 with each other or    with other unsaturated monomers, for example acrylonitrile/butadiene    copolymers, acrylonitrile/alkyl acrylate copolymers,    acrylonitrile/alkoxyalkyl acrylate or acrylonitrile/vinyl halide    copolymers or acrylonitrile/alkyl methacrylate/butadiene    terpolymers.-   12. Polymers derived from unsaturated alcohols and amines or the    acyl derivatives or acetals thereof, for example polyvinyl alcohol,    polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, polyvinyl    maleate, polyvinyl butyral, polyallyl phthalate or polyallyl    melamine; as well as their copolymers with olefins mentioned in    Section 2 above.-   13. Homopolymers and copolymers of cyclic ethers such as    polyalkylene glycols, polyethylene oxide, polypropylene oxide or    copolymers thereof with bisglycidyl ethers.-   14. Polyacetals such as polyoxymethylene and those    polyoxymethylenes, which contain ethylene oxide as a comonomer;    polyacetals modified with thermoplastic polyurethanes, acrylates or    MBS.-   15. Polyphenylene oxides and sulphides, and mixtures of    polyphenylene oxides with styrene polymers or polyamides.-   16. Polyurethanes derived from hydroxy-terminated polyethers,    polyesters or polybutadienes on the one hand and aliphatic or    aromatic polyisocyanates on the other, as well as precursors    thereof.-   17. Polyureas, polyimides, polyamide imides, polyether imides,    polyester imides, polyhydantoins and polybenzimidazoles.-   18. Polyesters derived from dicarboxylic acids and diols and/or from    hydroxycarboxylic acids or the corresponding lactones, for example    poly-β-hydroxybutyric acid, poly-β-hydroxyvaleric, polylactides,    particularly biodegradable polylactides or the corresponding    copolymers from 1-lactic acid and ε-caprolactone, acid polyethylene    terephthalate, polybutylene terephthalate,    poly-1,4-dimethylolcyclohexane terephthalate, polyalkylene    naphthalate (PAN) and polyhydroxybenzoates, as well as block    co-polyether esters derived from hydroxy-terminated polyethers; and    also polyesters modified with polycarbonates or MBS.-   19. Polyketones.-   20. Polysulphones, polyether sulphones and polyether ketones.-   21. Blends of the aforementioned polymers (polyblends), for example    PP/EPDM, Polyamide/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS, PC/ABS,    PBTP/ABS, PC/ASA, PC/PBT, PVC/CPE, PVC/acrylates, POM/thermoplastic    PUR, PC/thermoplastic PUR, POM/acrylate, POM/MBS, PPO/HIPS, PPO/PA    6.6 and copolymers, PA/HDPE, PA/PP, PA/PPO, PBT/PC/ABS or    PBT/PET/PC.-   22. Polycarbonates that correspond to the general formula:

-   -   Such polycarbonates are obtainable by interfacial processes or        by melt processes (catalytic transesterification). The        polycarbonate may be either branched or linear in structure and        may include any functional substituents. Polycarbonate        copolymers and polycarbonate blends are also within the scope of        the invention. The term polycarbonate should be interpreted as        inclusive of copolymers and blends with other thermoplastics.        Methods for the manufacture of polycarbonates are known, for        example, from U.S. Pat. Nos. 3,030,331; 3,169,121; 4,130,458;        4,263,201; 4,286,083; 4,552,704; 5,210,268; and 5,606,007. A        combination of two or more polycarbonates of different molecular        weights may be used.

Component d)

The composition of the present invention contains at least one phenolicantioxidant selected from the group defined below:

-   -   Alkylated monophenols, for example        2,6-di-tert-butyl-4-methylphenol,        2-tert-butyl-4,6-di-methylphenol,        2,6-di-tert-butyl-4-ethylphenol,        2,6-di-tert-butyl-4-n-butylphenol,        2,6-di-tert-butyl-4-isobutylphenol,        2,6-dicyclopentyl-4-methylphenol,        2-(α-methylcyclohexyl)-4,6-di-methylphenol,        2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol,        2,6-di-tert-butyl-4-methoxymethylphenol, nonylphenols which are        linear or branched in the side chains, for example        2,6-di-nonyl-4-methylphenol,        2,4-dimethyl-6-(1′-methylundec-1′-yl)phenol,        2,4-dimethyl-6-(1′-methylheptadec-1-yl)phenol,        2,4-dimethyl-6-(1′-methyl-tridec-1′-yl)phenol and mixtures        thereof;    -   Alkylthiomethylphenols, for example        2,4-dioctylthiomethyl-6-tert-butylphenol,        2,4-dioctyl-thiomethyl-6-methylphenol,        2,4-dioctylthiomethyl-6-ethylphenol,        2,6-di-dodecyl-thiomethyl-4-nonylphenol;    -   Hydroquinones and alkylated hydroquinones, for example        2,6-di-tert-butyl-4-methoxy-phenol,        2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone,        2,6-diphenyl-4-octadecyloxyphenol,        2,6-di-tert-butylhydroquinone,        2,5-di-tert-butyl-4-hydroxyanisole,        3,5-di-tert-butyl-4-hydroxyanisole,        3,5-di-tert-butyl-4-hydroxyphenyl stearate,        bis(3,5-di-tert-butyl-4-hydroxyphenyl) adipate;    -   Tocopherols, for example α-, β-, γ-, δ-tocopherol and mixtures        thereof (vitamin E);    -   Hydroxylated thiodiphenyl ethers, for example 2,        2′-thiobis(6-tert-butyl-4-methylphenol),        2,2′-thiobis(4-octylphenol),        4,4′-thiobis(6-tert-butyl-3-methylphenol),        4,4′-thiobis(6-tert-butyl-2-methylphenol),        4,4′-thiobis(3,6-di-sec-amylphenol),        4,4′-bis(2,6-dimethyl-4-hydroxyphenyl)disulphide;    -   Alkylidenebisphenols, for example 2,        2′-methylenebis(6-tert-butyl-4-methylphenol),        2,2′-methylenebis(6-tert-butyl-4-ethylphenol),        2,2′-methylenebis[4-methyl-6-(α-methylcyclohexyl)phenol],        2,2′-methylenebis(4-methyl-6-cyclohexylphenol),        2,2′-methylenebis(6-nonyl-4-methylphenol),        2,2′-methylenebis(4,6-di-tert-butylphenol),        2,2′-ethylidenebis(4,6-di-tert-butylphenol),        2,2′-ethylidenebis(6-tert-butyl-4-isobutylphenol),        2,2′-methylenebis[6-(α-methylbenzyl)-4-nonylphenol],        2,2′-methylenebis[6-(α,α-dimethylbenzyl)-4-nonylphenol],        4,4′-methylenebis(2,6-di-tert-butylphenol),        4,4′-methylenebis(6-tert-butyl-2-methylphenol),        1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane,        2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol,        1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane,        1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-3-n-dodecylmercaptobutane,        ethylene glycol        bis[3,3-bis(3′-tert-butyl-4′-hydroxyphenyl)butyrate],        bis(3-tert-butyl-4-hydroxy-5-methyl-phenyl)dicyclopentadiene,        bis[2-(3′-tert-butyl-2′-hydroxy-5′-methylbenzyl)-6-tert-butyl-4-methylphenyl]terephthalate,        1,1-bis-(3,5-dimethyl-2-hydroxyphenyl)butane,        2,2-bis(3,5-di-tert-butyl-4-hydroxyphenyl)propane,        2,2-bis-(5-tert-butyl-4-hydroxy-2-methylphenyl)-4-n-dodecylmercaptobutane,        1,1,5,5-tetra(5-tert-butyl-4-hydroxy-2-methylphenyl)pentane;    -   O-, N- and S-benzyl compounds, for example 3,        5,3′,5′-tetra-tert-butyl-4,4′-dihydroxydibenzyl ether,        octadecyl-4-hydroxy-3,5-dimethylbenzylmercaptoacetate,        tridecyl-4-hydroxy-3,5-di-tert-butylbenzylmercaptoacetate,        tris(3,5-di-tert-butyl-4-hydroxybenzyl)-amine,        bis(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)dithioterephthalate,        bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulphide,        isooctyl-3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate;    -   Hydroxybenzylated malonates, for example        dioctadecyl-2,2-bis(3,5-di-tert-butyl-2-hydroxybenzyl)malonate,        di-octadecyl-2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)malonate,        di-dodecylmercaptoethyl-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate,        bis[4-(1,1,3,3-tetramethylbutyl)phenyl]-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate;    -   Aromatic hydroxybenzyl compounds, for example 1,        3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene,        1,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetramethylbenzene,        2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol;    -   Triazine compounds, for example        2,4-bis(octylmercapto)-6-(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine,        2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine,        2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,3,5-triazine,        2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,2,3-triazine,        1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate,        1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate,        2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenylethyl)-1,3,5-triazine,        1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hexahydro-1,3,5-triazine,        1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl)isocyanurate;    -   Benzylphosphonates, for example        dimethyl-2,5-di-tert-butyl-4-hydroxybenzylphosphonate,        diethyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate,        dioctadecyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate,        dioctadecyl-5-tert-butyl-4-hydroxy-3-methylbenzylphosphonate,        the calcium salt of the monoethyl ester of        3,5-di-tert-butyl-4-hydroxybenzyl-phosphonic acid;    -   Acylaminophenols, for example 4-hydroxylauranilide,        4-hydroxystearanilide, octyl        N-(3,5-di-tert-butyl-4-hydroxyphenyl)carbamate;    -   Esters of -(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid        with mono- or polyhydric alcohols, e.g. with methanol, ethanol,        n-octanol, i-octanol, octadecanol, 1,6-hexanediol,        1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl        glycol, thiodiethylene glycol, diethylene glycol, triethylene        glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate,        N,N′-bis(hydroxyethyl)oxamide, 3-thiaundecanol,        3-thiapentadecanol, trimethylhexanediol, trimethylolpropane,        4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane, such        as commercially available products like Irganox® 1076;    -   Esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic        acid with mono- or polyhydric alcohols, e.g. with methanol,        ethanol, n-octanol, i-octanol, octadecanol, 1,6-hexanediol,        1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl        glycol, thiodiethylene glycol, diethylene glycol, triethylene        glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate,        N,N′-bis(hydroxyethyl)oxamide, 3-thiaundecanol,        3-thiapentadecanol, trimethylhexanediol, trimethylolpropane,        4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane;        3,9-bis[2-{3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane;    -   Esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid        with mono- or polyhydric alcohols, e.g. with methanol, ethanol,        octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene        glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene        glycol, diethylene glycol, triethylene glycol, pentaerythritol,        tris(hydroxyethyl)isocyanurate, N,N′-bis(hydroxyethyl)oxamide,        3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol,        trimethylolpropane,        4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane;    -   Esters of 3,5-di-tert-butyl-4-hydroxyphenyl acetic acid with        mono- or polyhydric alcohols, e.g. with methanol, ethanol,        octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene        glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene        glycol, diethylene glycol, triethylene glycol, pentaerythritol,        tris(hydroxyethyl)isocyanurate, N,N′-bis(2-hydroxyethyl)oxamide,        3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol,        trimethylolpropane,        4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane;    -   Amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid        e.g.        N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamide,        N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)trimethylenediamide,        N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazide,        N,N′-bis[2-(3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyloxy)ethyl]oxamide        (Naugard® XL-1, supplied by Uniroyal);    -   Ascorbic acid (vitamin C).

Preferred specific phenolic antioxidants according to Component d)include octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate(IRGANOX 1076),pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate](IRGANOX 1010), tris(3,5-di-tert-butyl-4-hydroxyphenyl)isocyanurate(IRGANOX 3114),1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-benzene(IRGANOX 1330),triethyleneglycol-bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)-propionate](IRGANOX 245), andN,N′-hexane-1,6-diyl-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide](IRGANOX 1098).

The phenolic additives of Component d) mentioned above are preferablycontained in an amount of 0.01 to 10.0%, especially 0.05 to 5.0%,relative to the weight of the polymer substrate according to Componentc).

Additional Components

The instant invention further pertains to a composition, whichcomprises, in addition to the components a), b) and c), as definedabove, as optional components further additives selected from the groupconsisting of so-called anti-dripping agents, polymer stabilizers andadditional flame-retardants, such as phosphorus containingflame-retardants, nitrogen containing flame-retardants, halogenatedflame-retardants and inorganic flame-retardants.

As mentioned above, the composition according to the invention mayadditionally contain one or more conventional additives, for exampleselected from pigments, dyes, plasticizers, antioxidants, thixotropicagents, levelling assistants, basic co-stabilizers, metal passivators,metal oxides, organophosphorus compounds, further light stabilizers andmixtures thereof, especially pigments, other antioxidants, calciumstearate, zinc stearate, UV absorbers of the 2-hydroxy-benzophenone,2-(2′-hydroxyphenyl)benzotriazole and/or2-(2-hydroxyphenyl)-1,3,5-triazine groups. More specific examples arethe following components:

-   1. Light stabilisers:    -   2-(2′-Hydroxyphenyl)benzotriazoles, for example        2-(2′-hydroxy-5′-methylphenyl)benzotriazole,        2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)benzotriazole,        2-(5′-tert-butyl-2′-hydroxyphenyl)benzotriazole,        2-(2′-hydroxy-5′-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole,        2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)-5-chlorobenzotriazole,        2-(3′-tert-butyl-2′-hydroxy-5′-methylphenyl)-5-chlorobenzotriazole,        2-(3′-sec-butyl-5′-tert-butyl-2′-hydroxyphenyl)benzotriazole,        2-(2′-hydroxy-4′-octyloxyphenyl)benzotriazole,        2-(3′,5′-di-tert-amyl-2′-hydroxyphenyl)benzotriazole,        2-(3′,5′-bis(α,α-dimethylbenzyl)-2′-hydroxyphenyl)benzotriazole,        2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)-5-chlorobenzotriazole,        2-(3′-tert-butyl-5′-[2-(2-ethylhexyloxy)carbonylethyl]-2′-hydroxyphenyl)-5-chlorobenzotriazole,        2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)-phenyl)-5-chlorobenzotriazole,        2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)-phenyl)benzotriazole,        2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)-benzotriazole,        2-(3′-tert-butyl-5′-[2-(2-ethylhexyloxy)carbonylethyl]-2′-hydroxyphenyl)-benzotriazole,        2-(3′-dodecyl-2′-hydroxy-5′-methylphenyl)benzotriazole,        2-(3′-tert-butyl-2′-hydroxy-5′-(2-isooctyloxycarbonylethyl)phenylbenzotriazole,        2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazole-2-ylphenol];        the transesterification product of        2-[3′-tert-butyl-5′-(2-methoxycarbonylethyl)-2′-hydroxyphenyl]-2H-benzotriazole        with polyethylene glycol 300;

-   -   where R=3′-tert-butyl-4′-hydroxy-5′-2H-benzotriazol-2-ylphenyl,        2-[2′-hydroxy-3′-(α,α-dimethylbenzyl)-5′-(1,1,3,3-tetramethylbutyl)phenyl]benzotriazole;        2-[2′-hydroxy-3′-(1,1,3,3-tetramethylbutyl)-5′-(α,α-dimethylbenzyl)phenyl]benzotriazole,        such as commercially available light stabilisers from the        Tinuvin® series, such as TINUVIN 234, 326, 329, 350, 360 or        TINUVIN 1577;    -   2-Hydroxybenzophenones, for example the 4-hydroxy, 4-methoxy,        4-octyloxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy,        4,2′,4′-trihydroxy and 2′-hydroxy-4,4′-dimethoxy derivatives;    -   Esters of substituted and unsubstituted benzoic acids, for        example 4-tert-butylphenyl salicylate, phenyl salicylate,        octylphenyl salicylate, dibenzoyl resorcinol,        bis(4-tert-butyl-benzoyl)resorcinol, benzoyl resorcinol,        2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate,        hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl        3,5-di-tert-butyl-4-hydroxybenzoate,        2-methyl-4,6-di-tert-butylphenyl        3,5-di-tert-butyl-4-hydroxybenzoate;    -   Acrylates, for example ethyl α-cyano-β,β-diphenylacrylate,        isooctyl α-cyano-β,β-diphenylacrylate, methyl        α-carbomethoxycinnamate, methyl        α-cyano-β-methyl-p-methoxy-cinnamate, butyl        α-cyano-β-methyl-p-methoxycinnamate, methyl        α-carbomethoxy-p-methoxycinnamate and        N-(β-carbomethoxy-β-cyanovinyl)-2-methylindoline;    -   Nickel compounds, for example nickel complexes of        2,2′-thiobis[4-(1,1,3,3-tetramethylbutyl)phenol], such as the        1:1 or 1:2 complex, with or without additional ligands such as        n-butylamine, triethanolamine or N-cyclohexyldiethanolamine,        nickel dibutyldithiocarbamate, nickel salts of the monoalkyl        esters, e.g. the methyl or ethyl ester, of        4-hydroxy-3,5-di-tert-butylbenzylphosphonic acid, nickel        complexes of ketoximes, e.g. of        2-hydroxy-4-methylphenylundecylketoxime, nickel complexes of        1-phenyl-4-lauroyl-5-hydroxypyrazole, with or without additional        ligands;    -   Oxamides, for example 4, 4′-dioctyloxyoxanilide,        2,2′-diethoxyoxanilide,        2,2′-dioctyloxy-5,5′-di-tert-butoxanilide,        2,2′-didodecyloxy-5,5′-di-tert-butoxanilide,        2-ethoxy-2′-ethyloxanilide,        N,N′-bis(3-dimethylaminopropyl)oxamide,        2-ethoxy-5-tert-butyl-2′-ethoxanilide and its mixture with        2-ethoxy-2′-ethyl-5,4′-di-tert-butoxanilide, mixtures of o- and        p-methoxy-disubstituted oxanilides and mixtures of o- and        p-ethoxy-disubstituted oxanilides;    -   2-(2-Hydroxyphenyl)-1,3,5-triazines, for example 2,        4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine,        2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,        2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,        2,4-bis(2-hydroxy-4-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine,        2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine,        2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,        2-(2-hydroxy-4-tridecyloxyphenyl)-4,6-bis-(2,4-dimethylphenyl)-1,3,5-triazine,        2-[2-hydroxy-4-(2-hydroxy-3-butyloxypropoxy)-phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine,        2-[2-hydroxy-4-(2-hydroxy-3-octyloxypropyloxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine,        2-[4-(dodecyloxy/tridecyloxy-2-hydroxypropoxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,        2-[2-hydroxy-4-(2-hydroxy-3-dodecyloxypropoxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,        2-(2-hydroxy-4-hexyloxy)phenyl-4,6-diphenyl-1,3,5-triazine,        2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine,        2,4,6-tris[2-hydroxy-4-(3-butoxy-2-hydroxypropoxy)phenyl]-1,3,5-triazine,        2-(2-hydroxyphenyl)-4-(4-methoxyphenyl)-6-phenyl-1,3,5-triazine,        2-{2-hydroxy-4-[3-(2-ethylhexyl-1-oxy)-2-hydroxypropyloxy]phenyl}-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine;

-   2. Metal deactivators, for example N,N′-diphenyloxamide,    N-salicylal-N′-salicyloyl hydrazine, N,N′-bis(salicyloyl)hydrazine,    N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine,    3-salicyloylamino-1,2,4-triazole, bis(benzylidene)oxalyl    dihydrazide, oxanilide, isophthaloyl dihydrazide, sebacoyl    bisphenylhydrazide, N,N′-diacetyladipoyl dihydrazide,    N,N′-bis(salicyloyl)oxalyl dihydrazide,    N,N′-bis(salicyloyl)thiopropionyl dihydrazide.

-   3. Further phosphites and phosphonites, for example triphenyl    phosphite, diphenylalkyl phosphites, phenyldialkyl phosphites,    tris(nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl    phosphite, distearylpentaerythritol diphosphite,    tris(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritol    diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol    diphosphite, bis(2,4-di-cumylphenyl)pentaerythritol diphosphite,    bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite,    diisodecyloxypentaerythritol diphosphite,    bis-(2,4-di-tert-butyl-6-methylphenyl)pentaerythritol diphosphite,    bis(2,4,6-tris(tert-butylphenyl)pentaerythritol diphosphite,    tristearyl sorbitol triphosphite, tetrakis(2,4-di-tert-butylphenyl)    4,4′-biphenylene diphosphonite,    6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenz[d,g]-1,3,2-dioxaphosphocin,    bis(2,4-di-tert-butyl-6-methylphenyl)methyl phosphite,    bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite,    6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenz[d,g]-1,3,2-dioxaphosphocin,    2,2′,2″-nitrilo[triethyltris(3,3″,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diyl)phosphite],    2-ethylhexyl(3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diyl)phosphite,    5-butyl-5-ethyl-2-(2,4,6-tri-tert-butylphenoxy)-1,3,2-dioxaphosphirane.    -   The following phosphites are especially preferred:    -   Tris(2,4-di-tert-butylphenyl) phosphite (lrgafos 168, Ciba        Inc.), tris(nonylphenyl) phosphite,

-   4. Further nitrones, for example N-benzyl-alpha-phenylnitrone,    N-ethyl-alpha-methylnitrone, N-octyl-alpha-heptylnitrone,    N-lauryl-alpha-undecyInitrone, N-tetradecyl-alpha-tridecylnitrone,    N-hexadecyl-alpha-pentadecyInitrone,    N-octadecyl-alpha-heptadecyInitrone,    N-hexadecyl-alpha-heptadecyInitrone,    N-ocatadecyl-alpha-pentadecyInitrone,    N-heptadecyl-alpha-heptadecyInitrone,    N-octadecyl-alpha-hexadecyInitrone, nitrone derived from    N,N-dialkylhydroxyamine derived from hydrogenated tallow amine.-   5. Thiosynergists, for example dilauryl thiodipropionate or    distearyl thiodipropionate.-   6. Peroxide scavengers, for example esters of 3-thiodipropionic    acid, for example the lauryl, stearyl, myristyl or tridecyl esters,    mercaptobenzimidazole or the zinc salt of 2-mercaptobenzimidazole,    zinc dibutyldithiocarbamate, dioctadecyl disulphide, pentaerythritol    tetrakis(β-dodecylmercapto)propionate.-   7. Polyamide stabilisers, for example copper salts in combination    with iodides and/or phosphorus compounds and salts of divalent    manganese.-   8. Basic co-stabilisers, for example melamine, polyvinylpyrrolidone,    dicyandiamide, triallyl cyanurate, urea derivatives, polyamides,    polyurethanes, alkali metal salts and alkaline earth metal salts of    higher fatty acids, for example calcium stearate, zinc stearate,    magnesium behenate, magnesium stearate, sodium ricinoleate and    potassium palmitate, antimony pyrocatecholate or zinc    pyrocatecholate.-   9. Nucleating agents, for example inorganic substances, such as    talcum, metal oxides, such as titanium dioxide or magnesium oxide,    phosphates, carbonates or sulphates of, preferably, alkaline earth    metals; organic compounds, such as mono- or polycarboxylic acids and    the salts thereof, e.g. 4-tert-butylbenzoic acid, adipic acid,    diphenylacetic acid, sodium succinate or sodium benzoate; polymeric    compounds, such as ionic copolymers (ionomers). Especially preferred    are 1,3:2,4-bis(3′,4′-dimethylbenzylidene)sorbitol,    1,3:2,4-di(paramethyldibenzylidene)sorbitol, and    1,3:2,4-di(benzylidene)sorbitol.-   10. Further fillers and reinforcing agents, for example calcium    carbonate, silicates, glass fibres, glass bulbs, stainless steel    fibres, aramide fibers, asbestos, talc, kaolin, mica, barium    sulphate, metal oxides and hydroxides, carbon black, graphite, wood    flour and flours or fibers of other natural products, synthetic    fibres.-   11. Other additives, for example blend compatibilizing agents,    plasticisers, lubricants, emulsifiers, pigments, rheology additives,    catalysts, flow-control agents, optical brighteners, flame proofing    agents, antistatic agents and blowing agents.-   12. Additional benzofuranones and indolinones, for example those    disclosed in U.S. Pat. Nos. 4,325,863; 4,338,244; 5,175,312;    5,216,052; or 5,252,643; DE-A-4316611; DE-A-4316622; DE-A-4316876;    EP-A-0589839 or EP-A-0591102 or    3-[4-(2-acetoxyethoxy)phenyl]-5,7-di-tert-butylbenzofuran-2-one,    5,7-di-tert-butyl-3-[4-(2-stearoyloxyethoxy)phenyl]benzofuran-2-one,    3,3′-bis[5,7-di-tert-butyl-3-(4-[2-hydroxyethoxy]phenyl)benzofuran-2-one],    5,7-di-tert-butyl-3-(4-ethoxyphenyl)benzofuran-2-one,    3-(4-acetoxy-3,5-dimethylphenyl)-5,7-di-tert-butylbenzofuran-2-one,    3-(3,5-dimethyl-4-pivaloyloxyphenyl)-5,7-di-tert-butylbenzofuran-2-one,    3-(3,4-dimethylphenyl)-5,7-di-tert-butyl-benzofuran-2-one,    3-(2,3-dimethylphenyl)-5,7-di-tert-butylbenzofuran-2-one.

According to a preferred embodiment the invention relates to acomposition, which additionally comprises further additives selectedfrom the group consisting of polymer stabilizers and additional flameretardants.

According to another embodiment, the invention relates to a compositionwhich additionally comprises as additional component so-calledanti-dripping agents.

These anti-dripping agents reduce the melt flow of the thermoplasticpolymer and inhibit the formation of drops at high temperatures. Variousreferences, such as U.S. Pat. No. 4,263,201, describe the addition ofanti-dripping agents to flame retardant compositions.

Suitable additives that inhibit the formation of drops at hightemperatures include glass fibers, polytetrafluoroethylene (PTFE), hightemperature elastomers, carbon fibers, glass spheres and the like.

The addition of polysiloxanes of different structures has been proposedin various references; cf. U.S. Pat. Nos. 6,660,787, 6,727,302 or6,730,720.

According to a preferred embodiment of the invention, the compositioncomprises an additional flame retardant component. Such additionalflame-retardants are known components, items of commerce or can beobtained by known methods. Halogen-free flame retardants are preferred.

According to a preferred embodiment, the composition comprises as anadditional flame retardant component the metal salt of hypophosphinicacid, as represented by the formula

in whichM represents (C₁-C₄alkyl)₄N, (C₁-C₄alkyl)₃NH, (C₂-C₄alkylOH)₄N,(C₂-C₄alkylOH)₃NH, (C₂-C₄alkylOH)₂N(CH₃)₂, (C₂-C₄alkylOH)₂NHCH₃,(C₆H₅)₄N, (C₆H₅)₃NH, (C₆H₅CH₃)₄N, (C₆H₅CH₃)₃NH, NH₄, an alkali metal orearth alkali metal ion, or an aluminium, zinc, iron or boron ion;m is a numeral from 1-3 and indicates the number of positive charges onM; andn is a numeral from 1-3 and indicates the number of phosphinic acidanions corresponding to M^(m+).

A highly preferred embodiment relates to a composition, which comprisesas additional flame retardant component the aluminium salt ofhypophosphinic acid.

Other representative phosphorus containing flame-retardants, in additionto the ones defined above with regard to components a) and b), are forexample:

Tetraphenyl resorcinol diphosphite (Fyrolflex® RDP, Akzo Nobel),resorcinol diphosphate oligomer(RDP), tetrakis(hydroxymethyl)phosphoniumsulphide, triphenyl phosphate,diethyl-N,N-bis(2-hydroxyethyl)-aminomethyl phosphonate, hydroxyalkylesters of phosphorus acids, salts of hypophosphoric acid (H₃PO₂) withsuitable cations, such as Ca²⁺, Zn²⁺or Al³⁺, ammonium polyphosphate(APP) or (Hostaflam® AP750), resorcinol diphosphate oligomer (RDP),phosphazene flame-retardants and ethylenediamine diphosphate (EDAP).

Nitrogen containing flame-retardants are, for example, isocyanurateflame-retardants, such as polyisocyanurate, esters of isocyanuric acidor isocyanurates. Representative examples are hydroxyalkylisocyanurates, such as tris-(2-hydroxyethyl)isocyanurate,tris(hydroxymethyl)isocyan urate, tris(3-hydroxy-n-proyl)isocyanurate ortriglycidyl isocyanurate.

Nitrogen containing flame-retardants include further melamine-basedflame-retardants. Representative examples are: melamine cyanurate,melamine borate, melamine phosphate, melamine pyrophosphate, melamineammonium polyphosphate, melamine ammonium pyrophosphate or dimelaminephosphate.

Further examples are: benzoguanamine, tris(hydroxyethyl) isocyanurate,allantoin, glycoluril, dimelamine phosphate, urea cyanurate, ammoniumpolyphosphate, a condensation product of melamine from the series melem,melam, melon and/or a higher condensed compound or a reaction product ofmelamine with phosphoric acid or a mixture thereof.

Suitable inorganic flame retardants include, for example, aluminumtrihydroxide (ATH), boehmite (AIOOH), magnesium dihydroxide (MDH), zincborates, CACO₃ or layered double hydroxides, optionally modified withorganic substituents.

Some organohalogen flame-retardants are, for example:

Polybrominated diphenyl oxide (DE-60F, Great Lakes Corp.),decabromodiphenyl oxide (DBDPO; Saytex® 102E),tris[3-bromo-2,2-bis(bromomethyl)propyl] phosphate (PB 370®, FMC Corp.),tris(2,3-dibromopropyl)phosphate, tris(2,3-dichloropropyl)phosphate,chlorendic acid, tetrachlorophthalic acid, tetrabromophthalic acid,poly-β-chloroethyl triphosphonate mixture, tetrabromobisphenol Abis(2,3-dibromopropyl ether) (PE68), brominated epoxy resin,ethylene-bis(tetrabromophthalimide) (Saytex® BT-93),bis(hexachlorocyclopentadieno)cyclooctane (Declorane Plus®), chlorinatedparaffins, octabromodiphenyl ether, hexachlorocyclopentadienederivatives, 1,2-bis(tribromophenoxy)ethane (FF680),tetrabromo-bisphenol A (Saytex® RB100), ethylenebis-(dibromo-norbornanedicarboximide) (Saytex® BN-451),bis-(hexachlorocycloentadeno) cyclooctane, PTFE,tris-(2,3-dibromopropyl)-isocyanurate, andethylene-bis-tetrabromophthalimide.

The flame-retardant mentioned above routinely combined with an inorganicoxide synergist. Most common for this use are zinc or antimony oxides,e.g. Sb₂O₃ or Sb₂O₅. Boron compounds are suitable, too.

The above-mentioned additional flame-retardant classes areadvantageously contained in the composition of the invention in anamount from about 0.5% to about 25.0% by weight of the organic polymersubstrate; for instance about 1.0% to about 20.0%; for example about5.0% to about 15.0% by weight of the polymer Component c) or based onthe total weight of the composition.

As mentioned above, the composition according to the invention mayadditionally contain one or more conventional additives, for exampleselected from polymeric dispersing agents, pigments, dyes, plasticizers,antioxidants, thixotropic agents, levelling assistants, basicco-stabilizers, metal passivators, metal oxides, organophosphoruscompounds, further light stabilizers and mixtures thereof, especiallypigments, phenolic antioxidants, calcium stearate, zinc stearate, UVabsorbers of the 2-hydroxybenzophenone,2-(2′-hydroxyphenyl)benzotriazole and/or2-(2-hydroxyphenyl)-1,3,5-triazine groups.

A suitable polymeric dispersing agent consists of a polymeric chain andat least one so-called anchoring group. The polymeric chain providessolubility properties within the polymeric substrate as well as stericstabilization and determines the compatibility with the polymer system,whereas the anchoring group is connected with the flame retardantmolecule itself.

Suitable polymeric dispersing agents are characterized by their effectof wetting solid flame retardant molecules, prevent viscosity build-upby dispersed flame retardant particles and prevent such particles fromreflocculation.

Suitable polymeric dispersing agents are commercially available itemse.g. under the product name SMA® Resins (Sartomer Corp.), such as thestyrene-maleic acid anhydride copolymers which correspond to the generalformula:

wherein —X— represents —O—, —NH— or —NR—, wherein R representsC₁-C₄alkyl or aryl, particularly phenyl, m is a numeral from 1-50 and nis a numeral from 1-5, particularly the product SMA® 1000P. This productis a low molecular weight styrene, maleic anhydride copolymer with anapproximately 1:1 mol ratio.

Other suitable products are so-called styrene maleic anhydridecopolymers, particularly the products SMA 1000F, 17352P, 2000F, 2000P,2625F, 2625P, 3000F, 3000P, 3840F, 17352F, 1440, 17352H, 1000H, 2625H,1440H, 1000H or 3000H or so-called styrene maleimide resins,particularly the products SMA 30001, 40001 or 20001.

According to an alternative embodiment, suitable polymeric dispersingagents are commercially available items under the product designationCiba®EFKA® “Processing aids and surface modifiers for polymer systems”,with a suitable molecular weight range is from 4 000-20 000.

A suitable product is an aliphatic polyether substituted by acidicgroups, as represented by the formula

Wherein R represents a C₈-C₁₈alkyl group and n represents a numeral from5 to 10, such as the product EFKA®8530 (aliphatic polyether with acidicgroups). Other suitable products are

-   -   EFKA®5054 (High molecular weight carboxylic acid salt)    -   EFKA®8462 (Modified polyacrylate)    -   EFKA®8530 (Aliphatic polyether with acidic groups)    -   EFKA®8531 (Modified polyester)    -   EFKA®8532 (Acidic polyether)    -   EFKA®8533 (Modified polyether)    -   EFKA®8534 (Partial amide and salt of high-molecular weight        unsaturated carboxylic acid)    -   EFKA®8536 (Polycarbonic acid-adduct, anionic).

The amount of dispersing agents present in the composition is notcritical and may vary within broad ranges. According to a preferredembodiment, the amount of dispersing agents present in the compositionis within a concentration range of 0.05-10.0 wt.-%, particularly 0.5-5.0wt.-%.

According to a preferred embodiment, the additional additives for thecompositions as defined above are selected from the group consisting ofprocessing stabilizers, such as the above-mentioned phosphites, theabove-mentioned phenolic antioxidants according to Component d), andlight stabilizers, such as benzotriazoles. Specific processingstabilizers include tris(2,4-di-tert-butylphenyl) phosphite (IRGAFOS168),3,9-bis(2,4-di-tert-butylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane(IRGAFOS 126),2,2′,2″-nitrilo[triethyl-tris(3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diyl)]phosphite(IRGAFOS 12), andtetrakis(2,4-di-tert-butylphenyl)[1,1-biphenyl]-4,4′-diylbisphosphonite(IRGAFOS P-EPQ). Specific light stabilizers include2-(2H-benzotriazole-2-yl)-4,6-bis(1-methyl-1-phenylethyl)-phenol(TINUVIN 234),2-(5-chloro(2H)-benzotriazole-2-yl)-4-(methyl)-6-(tert-butyl)phenol(TINUVIN 326),2-(2H-benzotriazole-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (TINUVIN329), 2-(2H-benzotriazole-2-yl)-4-(tert-butyl)-6-(sec-butyl)phenol(TINUVIN 350),2,2′-methylene-bis(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol)(TINUVIN 360), and2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol (TINUVIN1577), 2-(2′-hydroxy-5′-methyl-phenyl)benzotriazole (TINUVIN P),2-hydroxy-4-(octyloxy)benzophenone (CHIMASSORB 81),1,3-bis-[(2′-cyano-3′,3′-diphenylacryloyl)oxy]-2,2-bis-{[(2′-cyano-3′,3′-diphenylacryloyl)oxy]methyl}-propane(UVINUL 3030, BASF), ethyl-2-cyano-3,3-diphenylacrylate (UVINUL 3035,BASF), and (2-ethylhexyl)-2-cyano-3,3-diphenylacrylate (UVINUL 3039,BASF).

Process

The incorporation of the components defined above into the polymercomponent is carried out by known methods, such as dry blending in theform of a powder, or wet mixing in the form of solutions, dispersions orsuspensions for example in an inert solvent, water or oil. The additivecomponents a), b) and d) and optional further additives may beincorporated, for example, before or after molding or also by applyingthe dissolved or dispersed additive or additive mixture to the polymermaterial, with or without subsequent evaporation of the solvent or thesuspension/dispersion agent. They may be added directly into theprocessing apparatus, e.g. extruders, internal mixers, etc., as a drymixture or powder, or as a solution or dispersion or suspension or melt.

The addition of the additive components to the polymer substrate c) canbe carried out in customary mixing machines in which the polymer ismelted and mixed with the additives. Suitable machines are known tothose skilled in the art. They are predominantly mixers, kneaders andextruders.

The process is preferably carried out in an extruder by introducing theadditive during processing. Particularly preferred processing machinesare single-screw extruders, contra-rotating and co-rotating twin-screwextruders, planetary-gear extruders, ring extruders or co-kneaders. Itis also possible to use processing machines provided with at least onegas removal compartment to which a vacuum can be applied.

Suitable extruders and kneaders are described, for example, in Handbuchder Kunststoffextrusion, Vol. 1 Grundlagen, Editors F. Hensen, W.Knappe, H. Potente, 1989, pp. 3-7, ISBN:3-446-14339-4 (Vol. 2Extrusionsanlagen 1986, ISBN 3-446-14329-7).

For example, the screw length is 1-60 screw diameters, preferably 35-48screw diameters. The rotational speed of the screw is preferably 10-600rotations per minute (rpm), preferably 25-300 rpm.

The maximum throughput is dependent on the screw diameter, therotational speed and the driving force. The process of the presentinvention can also be carried out at a level lower than maximumthroughput by varying the parameters mentioned or employing weighingmachines delivering dosage amounts.

If a plurality of components is added, these can be premixed or addedindividually.

The additive components a), b) and d) and optional further additives canalso be sprayed onto the polymer substrate c). The additive mixturedilutes other additives, for example the conventional additivesindicated above, or their melts so that they can be sprayed alsotogether with these additives onto the polymer substrate. Addition byspraying during the deactivation of the polymerisation catalysts isparticularly advantageous; in this case, the steam evolved may be usedfor deactivation of the catalyst. In the case of spherically polymerisedpolyolefins it may, for example, be advantageous to apply the additivesof the invention, optionally together with other additives, by spraying.

The additive components a), b) and d) and optional further additives canalso be added to the polymer in the form of a master batch(“concentrate”) which contains the components in a concentration of, forexample, about 10.0% to about 60.0% and preferably 5.0% to about 40.0%by weight incorporated in a polymer. The polymer is not necessarily ofidentical structure than the polymer where the additives are addedfinally. In such operations, the polymer can be used in the form ofpowder, granules, solutions, and suspensions or in the form of lattices.

Incorporation can take place prior to or during the shaping operation.The materials containing the additives of the invention described hereinpreferably are used for the production of molded articles, for exampleroto-molded articles, injection molded articles, profiles and the like,and especially a fiber, spun melt non-woven, film or foam.

FURTHER EMBODIMENTS

A further embodiment of the invention relates to an additive mixture,which comprises

-   -   a) At least one polyphosphate salt of a 1,3,5-triazine compound        of the formula (I),        -   Wherein T represents a 1,3,5-triazine compound; and        -   p represents a numeral greater than 3; and    -   b) At least one natural or synthetic phyllosilicate or a mixture        thereof; and    -   d) Phenolic antioxidants.

The components a), b) and d) are admixed to the polymer substrate c) inconcentrations of 0.05-30.0 wt. %, preferably 0.1-20.0 wt. % forcomponent a), 0.5-40.0 wt. %, preferably 1.0-25 wt. % for component b),and 0.01-10.0 wt. %, preferably 0.05-5.0 wt. % for Component d).

The preferred weight ratio of components a):b):c) is in the range40:1:1-1:2:1, preferably 20:1:1-1:1:1.

According to a preferred embodiment, the weight ratio of thepolyphosphate component a) to the phyllosilicate component b) is betweenabout 2:1 to 20:1. 100 parts of the polymer substrate c) contain about1-40 parts of the additive mixture defined above.

A further embodiment of the invention relates to process for impartingflame retardancy to a polymer substrate, which process comprises addingto a polymer substrate the mixture defined above.

A preferred embodiment of the invention relates to process for impartingflame retardancy to a thermoplastic polymer substrate selected from thegroup consisting of polyamides and copolyamides, which process comprisesadding to a polymer substrate the additive mixture defined above.

The following Examples illustrate the invention:

Examples Components

Polyamide 6 (PA 6): Zyte107301 NC010, Dupont de Nemours InternationalGenève Suisse;Natural montmorillonite clay modified with stearylbenzyldimethylammoniumchloride (“modified clay”): Nanofil®, Rockwood Additives Ltd., Moosburg,Germany;Melamine polyphosphate: Melapur 200®, Ciba;Antioxidant blend of tris-(2,4-di-tert-butylphenyl)phosphite andN,N′-hexane-1,6-diyl-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionamide]:Ciba® Irganox® B1171.

Test Methods to Assess Flame Retardancy

The UL 94 test is performed according to the general rules described in“Flammability of Plastic Materials for Parts in Devices and Appliances”,5^(th) edition, Oct. 29, 1996. The ratings according to the UL 94 V testare compiled in the following table (times are indicated for onespecimen):

Rating After-flame Time Burning Drips V-0 <10 s No V-1 <30 s No V-2 <30s Yes n.c. (=not >30 s classified)

Standard Procedure/Examples

The samples are prepared by mechanically mixing dried PA 6 (80° C., 18hand vacuum) with the antioxidant blend (0.25%) and differentconcentrations of the organoclay and flame retardant. Melt compound iscarried out in a single-screw laboratory extruder (Brabender PLE 330plasticorder, diameter: 20, L/D:25). The temperature settings fromhopper to die are 220°, 230°, 240° and 250° C. The screw rotation speedis maintained at 20 rpm. The standard test specimen are obtained from anArburg 320 S-800-150 injection molding machine (Lossburg, Germany). Thebarrel zone temperatures are set in the range of 250°-265° C. The moldtemperature is kept at 80° C. and the injection pressure is 80 bar.

Unless stated otherwise, all experiments of each series are carried outunder identical conditions to ensure comparability (e.g. temperatureprofiles, screw geometries, addition of flame retardant additives,injection-molding parameters, etc.). All amounts are listed by theirweight amounts and are based on the plastic molding compositionincluding the flame retardant(s) and further additives. The burningtimes are given as sum of burning times for 5 specimen.

TABLE 1 Total Burning UL-94 Example No. Composition Time [sec]Classification 1 (Referential) PA-6 666 n.c. 2 (Referential) PA-6 + 479n.c. 1.0% Modified Clay 3 (Referential) PA-6 + 437 n.c. 5.0% ModifiedClay 4 (Referential) PA-6 + 138 n.c. 7.5% MELAPUR 200 5 (Referential)PA-6 + 153 n.c. 12.5% MELAPUR 200 6 PA-6 + 53 V-2 6.5% MELAPUR 200 +1.0% Modified Clay 7 PA-6 + 41 V-2 9.0% MELAPUR 200 + 1.0% Modified Clay

In another series of experiments samples are prepared by mechanicallymixing dried PA 6 (80° C., 18 h, vacuum) with the antioxidant blend(0.25%) and different concentrations of the organoclay (Nanofil 9) andflame retardant. Melt compounding is performed on a twin screw extruderHaake Rheomex PTW 16, L/D=25 (240-235-235-235-235-230 barrel/dietemperatures and 150 rpm, experiment 13-14 at 200 rpm). Standard testsamples are obtained from an Arburg 320 S-800-150 injection moldingmachine as described in Examples 1-7. In addition to the flame testsmechanical properties (tensile strength, elongation at break, tensilemodulus) are measured according to ISO 527.

TABLE 2 Total Elon- Burning UL-94 Tensile gation Tensile Example TimeClassifi- Strength at Break Modulus No. Composition [sec] cation [MPa][%] [MPa]  8 PA-6 n.d. n.c. 71.4 23.2 2726 (Refer- ential)  9 PA-6 +1.0% 237 n.c. 69.4  2.8 3027 (Refer- modified ential) clay 10 PA-6 +1.0%  38 V-2 81.9  8.0 3426 modified clay + 4.0% MELAPUR 200 11 PA-6 +0.5%  55 V-2 80.7  7.5 3421 modified clay + 6.0% MELAPUR 200 12 PA-6 +1.0%  36 V-2 73.7  2.1 3476 modified clay + 6.0% MELAPUR 200 13 PA-6 + 25 V-2 51.5  1.6 3498 20.0% MELAPUR 200 14 PA-6 + 1.0%  69 V-2 79.5 2.4 3873 modified clay + 20.0% MELAPUR 200 The inventive compositions10-14 show improved mechanical properties (high modulus and tensilestrength) at good flame retardancy.

1. A composition, which comprises a) At least one polyphosphate salt ofa 1,3,5-triazine compound of the formula (I)

Wherein T represents a 1,3,5-triazine compound and p represents anumeral greater than 3; b) At least one natural or syntheticphyllosilicate or a mixture thereof; c) A polymer substrate and d)Phenolic antioxidants.
 2. A composition according to claim 1, whichcomprises a) At least one polyphosphate salt of a 1,3,5-triazinecompound (I), wherein p represents a numeral greater than 3 and the1,3,5-triazine content is higher than 1.0 mol 1,3,5-triazine compoundper mol of phosphorus atom; b) At least one layered silicate; c) Athermoplastic polymer substrate and d) Phenolic antioxidants.
 3. Acomposition according to claim 1, which comprises a) At least onepolyphosphate salt of a 1,3,5-triazine compound (I), wherein prepresents a numeral greater than 10 and the 1,3,5-triazine content ishigher than 1.1 mol 1,3,5-triazine compound per mol of phosphorus atom;b) At least one unmodified layered silicate selected from the groupconsisting of montmorillonite, bentonite, beidelite, mica, hectorite,saponite, nontronite, sauconite, vermiculite, ledikite, magadite,kenyaite, stevensite, volkonskoite, hydrotalcite, illite, kaolinite,wollastonite, attapulcite, talcum, silica and mixtures thereof; c) Athermoplastic polymer substrate and d) Phenolic antioxidants.
 4. Acomposition according to claim 1, which comprises a) At least onepolyphosphate salt of a 1,3,5-triazine compound (I), wherein prepresents a numeral greater than 10 and the 1,3,5-triazine content ishigher than 1.1 mol 1,3,5-triazine compound per mol of phosphorus atom;b) At least one layered silicate selected from the group consisting ofmontmorillonite, bentonite, beidelite, mica, hectorite, saponite,nontronite, sauconite, vermiculite, ledikite, magadite, kenyaite,stevensite, volkonskoite, hydrotalcite, illite, kaolinite, wollastonite,attapulgite, talcum, silica and mixtures thereof modified by anammonium, amine, a phosphonium, sulphonium or a siloxane compound; c) Athermoplastic polymer substrate and d) Phenolic antioxidants.
 5. Acomposition according to claim 1, which comprises a) At least onepolyphosphate salt of a 1,3,5-triazine compound (I), wherein prepresents a numeral greater than 10 and the 1,3,5-triazine content ishigher than 1.1 mol 1,3,5-triazine compound per mol of phosphorus atom;b) At least one unmodified layered silicate selected from the groupconsisting of montmorillonite, bentonite, beidelite, mica, hectorite,saponite, nontronite, sauconite, vermiculite, ledikite, magadite,kenyaite, stevensite, volkonskoite, hydrotalcite and mixtures thereof;c) A thermoplastic polymer substrate selected from the group consistingof polyamides and copolyamides; and d) A phenolic antioxidant selectedfrom the group consisting of octadecyl3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate,pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],tris(3,5-di-tert-butyl-4-hydroxyphenyl)isocyanurate,1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene,triethyleneglycol-bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate]andN,N′-hexane-1,6-diyl-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide].6. (canceled)
 7. A composition according to claim 1, wherein the weightratio of components a):b):c) is in the range from 40:1:1-1:2:1.
 8. Acomposition according to claim 1, wherein the weight ratio of componentsa):b):c) in the range from 20:1:1-1:1:1.
 9. A mixture, which comprisesa) At least one polyphosphate salt of a 1,3,5-triazine compound of theformula (I)

Wherein T represents a 1,3,5-triazine compound and p represents anumeral greater than 3; b) At least one natural or syntheticphyllosilicate or a mixture thereof and d) Phenolic antioxidants.
 10. Aprocess for imparting flame retardancy to a polymer substrate, whichprocess comprises adding to a polymer substrate a mixture according toclaim
 9. 11. A process for imparting flame retardancy to a thermoplasticpolymer substrate selected from the group consisting of polyamides andcopolyamides, which process comprises adding to the polymer substrate amixture according to claims 9.